Sadiq Khan said that the drop in workers and tourists coming to London during the summer should be blamed on climate change.
The capital saw a drop in footfall of 76% in July, which hit the economy, as less people used services and transport around the city.
This was when record temperatures of more than 40°C were experienced throughout London, which the mayor has linked to the plunge in visitors.
He stressed that normally 518,000 workers would be expected but only 385,640 were present.
“For the first time ever, London overheated. Vicious wildfires almost overwhelmed emergency services – the busiest day of the year for the London fire brigade since the Second World War,” he stated.
“Infrastructure was crippled by extreme heat. We also saw a dramatic drop in footfall across central London to the detriment of our businesses. When we look back at this period of history, no-one will be able to claim with any credibility that we were not given fair warning – that we could not see disaster bearing down on us.”
London has a target of net zero by 2030 – two decades ahead of the rest of the UK – which Mr Khan stated would not be possible without heavy private investment.
He implored: “To meet our 2030 net zero target, London will need to go much further, much faster.
“Our estimate puts the figure in excess of £75 billion worth of investment. We simply can’t deliver that without the private sector, without you.
“Of course, I know you’re all dealing with inflationary pressures right now but there are huge opportunities and rewards to be seized by accelerating our efforts to achieve net zero by 2030.”